Stenotic lesions may comprise a hard, calcified substance and/or a softer thrombus material, each of which forms on the lumen walls of a blood vessel and restricts blood flow therethrough. Intraluminal treatments such as balloon angioplasty, stent deployment, atherectomy, and thrombectomy are well known and have been proven effective in the treatment of such stenotic lesions. These treatments often involve the insertion of a therapy catheter into a patient's vasculature.
One class of vascular catheters used to treat stenotic lesions is distal protection devices (DPD's). DPD's include, but are not limited to, filter devices and occluder devices. Filter devices are positioned distally from a stenoic lesion to capture stenotic debris that may be released during an intraluminal treatment, such as a balloon angioplasty or a thrombectomy. An occluder device is positioned distally from a stenotic lesion and may be used to block stenotic debris released during an intraluminal treatment, to catch a blood clot when pulled from a blood vessel, and the like.
One type of DPD utilizes a “push-pull” mechanism to deploy the apparatus at the distal end of the DPD. This type of DPD comprises an inner member such as a core wire or guidewire housed within an outer hollow sheath or hypo tube. Either the core wire or the hypo tube is attached to, for example, a filter of the filter device or an occluder of the occluder device. During an intraluminal treatment, the DPD is inserted into a patient's blood vessel until the filter or occluder is located distal to the lesion. By coaxially pushing or pulling the core wire and/or hypo tube relative to each other, the filter or occluder is expanded to an operational diameter. Once treatment is completed, the core wire and/or hypo tube are again coaxially pulled or pushed relative to each other and the filter or occluder is contracted to a removable diameter and the DPD is removed from the patient.
Deployment of DPD's that utilize push/pull mechanisms without damage to the DPD's is difficult. Certain DPD devices utilize fine core wire, such as those having a diameter of 0.013 inches or less, and fine hypo tubes, such as those having a diameter of 0.014 inches or less, both of which may be easily crimped or kinked. In addition, such DPD's may require 1.0 or more pound force to move the hypo tube relative to the core wire, especially when the DPD is disposed through tortuous vasculature. Further, surgical-grade coatings may be applied to such devices for a variety of purposes, such as to reduce trauma to surrounding tissue and/or to reduce risk of infection. If precautions are not taken, the coating may be scraped off the devices during deployment.
Other intraluminal devices also utilize coaxial push and/or pull mechanisms for deployment. For example, one class of self-expanding tubular stents is mounted on an inner catheter and is held in a collapsed configuration by a slidable sheath. Typically, the stent is released in a blood vessel by sliding the sheath proximally off the stent while holding the inner catheter in a fixed longitudinal position in the patient. Current methods of deploying the stent, however, such as sliding thumb buttons and telescoping hypodermic tubes, may cause unintentional advancement of the inner catheter through the sheath and, hence, unintentional misplacement of the stent.
Accordingly, it is desirable to provide a control handle that is configured to accurately deploy an intraluminal device that utilizes a push and/or pull mechanism for deployment. It is also desirable to provide a control handle that does not buckle or kink the inner member and does not scrape off any surgical-grade coating applied to the outer sheath and/or the inner member. Further, it is desirable to provide a control handle that may be removed completely from the intraluminal device during a medical procedure so that the device may be inserted into or removed from a patient or so that one or more other intraluminal procedures may be performed. Other desirable features and characteristics of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings.